Set mark eliminator



Jan. 12, 1954 c. R. BEALL ETAL SET MARK ELIMINATOR 3 Sheets-Sheet 1 Filed March 4, 1949 aw WWW.

M; Z 7 4 "we 5 R 3 m im mm L m w M a I W W a M wwww ATTOR N EYS Jan. 12, 1954 c. R. BEALL ET AL SET MARK ELIMINATOR I5 Sheets-Sheet 2 Filed March 4, 1949 LuiherBJZqyn/olds id CharlesR.BecvlL W fim%% ATTORNEYj Jan. 12, 1954 c. R. BEALL ET AL SET MARK ELIMINATOR 5 Sheets-Sheet 3 Filed March 4, 1949 arm/mm IEMFEUY fifTMADfD BREAK RELAY awue/rvtoul LwfherB.Re zvolds 3 C7t0u-lesR.Bcall MW wmww ATTORNEYS Patented Jan. 12, 1954 Charles B. .Beall and Luther B. Reynolds, La

Grange, Ga., assignors toWest PointManufacturing Company, West Point, 6a., a corporation of Alabama Application March 4, 1949, Serial No.79;644

"1 Claim. 1

This invention relates to looms, and more particularly to let-off mechanisms for looms. T,his invention further relates to a method of ,weavi-ng.

\ "During the weaving of textiles, the warp is commonly subjected to tension between the warp beam and the cloth take-up roller. In the case of many yarns such as those spun of short fibers .of wool .or cotton, and extruded filaments, such as those of cellulose acetate, the warp tension causes the warp to .set or stretch during overnight and other periods of shutdown. When a ,loom is started after a period of shutdown, the

first several (filling threads, due to the set of the warp and the resulting slackening of ten- .sion, are not spaced .similarly to the last filling threads inserted preceding shutdown. The resulting unevenness in filling thread spacing is known as .a set mark, and is the cause .of rejection of considerable quantities of cloth.

It is an object, therefore, of the present in vention to provide a method of operating looms to prevent the formation of set marks. More "specifically, it is an object of this invention .to prevent the formation of set marks by delaying let-off of the warp when a loom is started, until the action of the cloth take-up roller has comjpen's'ated for any set of the warp resulting from "shutdown.

'It is'a "further object of this invention to .provide means, readily adaptable to conventional loomsfi'to eliminate the Jformation .of set marks.

:More specifically, fit is .an object to provide "meansona loomlfor rendering the let-off mechanism of the loom inoperative for any desired length of time.

It is a "further object .to provide mechanical "meansfor temporarily rendering inoperative vthe The "invention and the'nov'el features thereof "willbest'be'made clear from the following description and the "accompanying drawings, in which:

' "Figure 111's aside view "of a conventional loom,

*cprovided with a preferred embodiment of. the

present" invention;

Figure 2 is a sectional plan view taken along the line 2-2 .of Figure 1;

Figure 3 is an enlarged detail view with parts broken away, showing the let-off mechanism of the loom of Figure land the drive therefor;

Figure 4 is ,a perspective view of the drive slot :member-of vthe let-off mechanism of Figure 3,;

Figure .5 is a section taken on the line 5-,5 in Figure .3;

Figure 6 is a sectional view taken on the line 6-6 in Figure 3;

Figure 7 is a section taken along the line 'I-T in Figure .6;

Figure 8 is a sectional view taken along the line 8-8 in Figure 3, further showing details ,of

the let-011 mechanism drive;

Figure 9 is a side view .of a loom provided with another embodiment of the present invention,

employing electrically operated means .to deactivate the let-off mechanism; 7

Figure 10 is an enlarged detail view of .the let- ;oif mechanism of the .loom of Figure 9, and

Figure 11 is a diagrammatic .view of .still another modification of the present invention, em- ,ploying time-controlled electrically operated means to deactivate the let-off mechanism.

Referring to the drawings, Figure 1 shows a preferred embodiment .of .the invention incorporated into a conventional loom, .such as a Draper X Model loom. The loom comprises the .usual parts, including the frame H, lay 12, lay sword I3, and shipper lever .14. Suitably journailed upon frame I l is the warp beam l5 ,-.dri.v.en through the vgear .16 (as best shown in. Figure .8) by .a let-off mechanism designated generally as 1| 1. The let-off mechanism [1 comprises the bearing 18 mountedin frame ill and the shaft 19 suitably journallejd therein. At the inner end of shaft 1.9 is fixed the gear 20, in driving relationship with gear 16, and suitably spaced therefrom on shaft I9 is mounted the ratchet wheel 2|. 7 The pawl carrier 22 is rotatably mounted upon shaft 1,9 adjacent ratchet .wheel .21. Fixed .to :the outer end of pawl carrier 22 and offset therefrom is the .pawl 23, in driving relationship with ratchet wheel 2.1. From the hub end of pawl carrier 22 extends the crank '24. The bracket .25, depending from "frame ll, supports the housing 25, wherein the shaft 21 is rotatablysupported, andthe cranks 28 and '29 ailixed thereto. Crank 24 is connected in driving relationship .to crank '28 by'link 38.

The rocker arms] is fixedto thelay rock shaft 32, and provided at its outer end with the pin 33. Pin 33 engages the drive slot member 34 by means of the drive slot 35, which comprises the oifset enlarged section 33. Drive slot member 34 is fixed to the link 31, by which it is connected to crank 29 in driving relationship. Also suitably journalled upon frame I is the traverse shaft 38, to which is fixed the treadle 39 and the crank 40. The outer end of crank 40 is provided with the pad 41, positioned and adapted to engage the under side of drive slot member 34.

A modification of the invention is illustrated in Figure 9, wherein is shown the warp beam l5, rotated through gear i6 by the let-off mechanism I1, comprising the ratchet wheel 2| and pawl 23. The pawl 23 is linked to plunger 42 of the solenoid 43 by the rod 44, which may be slotted at its lower end to prevent interference with the normal functioning of the pawl 23, as may best be seen in Figure 107 The solenoid 43 may conveniently be mounted upon frame H, as shown.

.The wires 45 connect solenoid 43 to a source of i power (not shown) and to the button switch 46, for convenience incorporated into shipper lever A still further modification of the invention is shown diagrammatically in Figure 11, wherein in circuit with solenoid 43 and button switch 46 are a plurality of the retarded break relays 41, and the selector switch 48, operable to place a selected one of the retarded break relays in circult with the solenoid.

During ordinary operation of a loom, the warp is tensioned between the cloth take-up roller (not shown) and warp beam [5. The warp beam I is restrained from rotating freely to relieve such tension, as by a friction brake or similar device.

The warp beam is positively rotated against the influence of such restraint to feed the warp at a rate coordinated with the cloth take-up to maintain the desired warp tension. In the loom shown, the warp beam [5 is rotated by the reciprocating action of pawl 23 on ratchet wheel 2 I. Pawl carrier 22 and pawl 23 are reciprocated by crank 24, driven by rocker arm 3| through pin 33, drive slot member 34, link 31, bell cranks 28 and 29, and link 39.

The pin 33 normally engages member 34 by means of the drive slot 35, which is designed to convey only so much of the reciprocating movement of rocker arm 3| as is desired to operate the pawl 23.

When the loom is started after a considerable period of shutdown, the warp has set and the tension therein slackened. In order to compensate for the set and return to the desired tension as soon as possible, it has been found effective to maintain the warp beam stationary through the weaving of the first several picks, whereby the action of the cloth takeup roller brings the warp tension up to the desired value. It has further been found that the adoption of this expedient eliminates the formation of set marks in the fabric, and the spacing between the filler threads inserted both before and after shutdown is uniform.

This end is attained in the preferred embodiment of this invention by means of the offset enlarged section 36 of drive slot 35. Pad is so positioned that depression of the treadle 21 raises drive slot member 34 from its normal position, so that pin 33 no longer engages drive slot 35, but reciprocates within the confines of the ofiset enlarged section 36 of drive slot 35, as may be seen in doted lines in Figure 1. The enlarged section 36 is designedto be adequate in size to permit the full throw of pin 33 without resultant movement of link 31.

-' of a set mark in the fabric obviated. The treadle 39 may then be released, and drive slot member 34 allowed to fall back to its normal position, whereby the let-off mechanism I1 is again activated and normal operation of the loom resumed.

In the operation of the modification shown in Figures 9 and 10, the action of pawl 23 on ratchet wheel 2! may be prevented by the rod 44, adapted and disposed to lift and hold pawl 23 out of engagement with ratchet wheel 2| as the pawl 23 reciprocates. The movement of rod 44 is effected by retraction of the plunger 42, occasioned by energization of the solenoid 43.

Upon restarting the loom by means of shipper lever [4, the operator may depress button switch 46, thereby energizing solenoid 43, and by'the resulting disengagement of pawl 23 delay functioning of the let-oil mechanism 11 until button switch 43 is released, whereupon the solenoid 43 is deenergized and the pawl 23 permitted to fall under the influence of gravity into normal engagement with the ratchet wheel 2|.

The necessary time interval for deactivation of the let-off mechanism 11 to prevent the formation of a set mark varies with the period of shutdown, the type of yarn or filament being woven, and other variables. This interval may vary from that necessary to weave two or three picks to the time required to weave twelve or more picks. It has been found that a moderately experienced operator may accurately judge and effectuate the necessary time delay in activating the let-off mechanism by means of the modifications of the invention above described. The period of delay between the starting of the loom and the starting of the let-oil mechanism may be accurately and automatically predetermined, however, by means of the further modification diagrammatically illustrated in Figure 11. In this modification, the push button of button switch 46 is depressed simultaneously with the starting of the loom, whereupon a circuit is set up through the then closed contacts of the retarded break relay 41 and also through the pawl actuating solenoid 43. Energization of the latter immediately effects disengagement of the pawl 23 from the ratchet wheel 2|, A shunt circuit is also set up through the retarded coil of the retarded break relay 41, and when the coil is completely energized its contacts will open and deenergize the pawl actuating solenoid 43, whereupon the'pawl falls under the influence of gravity into engagement with the ratchet wheel 2|. By providing a. plurality of retarded break relays 41, each operable to open its contacts after a different time interval, and selecting the desired retarded break relay by means of the selector switch 48, the period of time during which the pawl is held out of engagement may be accurately determined and preselected by the operator before starting the loom. Obviously, any equivalent time delay circuit opening devices may be employed instead of the retarded break relays mentioned above.

In the event of a shutdown of such short duration as not to cause the warp to set, it will be apparent that the loom may be started without the use of the mechanism of this invention, so that functioning of the let-off mechanism begins simultaneously with the functioning of the loom.

I Will thus be seen that there has been provided by this invention a method and apparatus in which the various objects hereinbefore set forth together with many practical advantages are successfully achieved. As various possible embodiments may be made of the mechanical features of the above invention and as the method herein described may be varied in the various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

In combination with a loom, a Warp beam, a ratchet Wheel and actuating pawl for rotating said warp beam to let oil the warp, a reciprocating pawl carrier driving said actuating pawl, a rocker arm fixed to the lay rock shaft of said loom, a pin extending from the outer end of said 20 rocker arm, a mechanical linkage between said pin and said pawl carrier to actuate said pawl carrier by means of said pin, said linkage comprising a drive slot enclosing said pin, and mechanical means for temporarily disengaging said pin from said drive slot while said loom is operating.

CHARLES R. BEALL.

LUTHER B. REYNOLDS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date- 710,024 Stimpson Sept. 30, 1902 781,681 Roper Feb. 7, 1905 807,721 Carver Dec. 19, 1905 829,689 Benson Aug. 28, 1906 843,181 Roper Feb. 5, 1907 1,427,636 Rhoads Aug. .29, 1922 1,620,175 Wakefield Mar. 8, 1927 2,421,539 Clarke June 3, 1947 

